I didn't realize that 150 wasn't made in WC. Interesting trade off between a WC 144 and W150, weight for width. I would probably go for the 144 WC. I think the reduced weight will make it more fun to sail, and at least partly make up for the reduced width compared to the 150. I'm pretty sure both with an 11m2 rig and the same fin would plane up in 7 knots.
The 150 might plane up tiny tiny bit earlier (again, for the team to answer) but I would rather trade off that very marginal planing ability for a livelier, lighter board which is going to be more fun when the wind picks up a bit.
JP Super-X 106l, North F8 Ram: 5.8m,